FCDA and the Department of Defense cooperated to obtain data on blast loading and structural response of dome-shaped structures. FCDA tested three such structures which were 50 feet in diameter with walls consisting of 6 inches of reinforced concrete. There were no interior supports. (See slide No. 17) The structures were located at anticipated pressure ranges of 20, 35, and 70 pounds per square inch. The blast caused no damage to the dome at 20 pounds per square inch, and appeared as shown in slide No. 17. The dome at 70 pounds per square inch was destroyed as is shown in slide No. 18, and the dome at 35 pounds per square inch was also badly damaged. The results obtained were as anticipated and verified our theoretical calculations. Actually, the pressures went a little higher than we had anticipated. Designs and specifications for dome shelters are being developed based on data obtained from these tests of the pilot structures. To provide a clearer concept of the test dome, a model has been fabricated and is on display in the front part of the room. As an integral part of the group shelter, the door must be capable of allowing a large number of persons rapid access to a shelter and must provide a blast-resistant pressure seal. A steel door was designed and tested under the sponsorship of FCDA to determine its effectiveness in providing protection to occupants of a shelter. (See slides Nos. 19, 20, and 21.) The door is hinged at the bottom and drops down into 25978-38-pt. 1- -9 |